LR65Pb
Active Member
- Joined
- Mar 9, 2015
- Messages
- 31
I've looked, searched forums and googled for AR30A1 specific reload data and very little is available. If I missed it, I apologize, but since I'm new to reloading the 300 Win Mag, some of the information I'll be posting may help another newbie that has the same problem.
The gun is an Armalite AR30A1 Target version of the .300 Win Mag. It has a 24" barrel, 1:10 twist rate and a factory break. I've added an Atlas bipod as well as a monopod on the stock. It comes standard with a long 20 moa rail and I've mounted an SIII 10-50x62 mm Sightron Mildot reticle scope. What I could not find posted was the chamber length and at what point the COAL would touch the lands. I've spent several days, learning and reloading, using H-1000 and the Hornady 208 A-max bullet. I've had excellent results with the A-max in my 6.5 Grendels, so I stuck with it.
What I didn't know was best seating depth, COAL, powder weight, etc specifically relating to the AR30A1. I loaded 5 pieces of brass at each powder weight in increments of .5 grains, beginning at 74 and stopping at 78.5. I also loaded 8 each in the 77 to 78.5 grain range with various COAL varying from 3.545, .090 off touching lands, to 3.632, .002 off lands.
My range is next door to my house. A close friend owns 600 acress and I've set up AR500 silhouette steel at every 100 yds from 100 to 1300 yards. Same target is used for 400 to 1300 yards. I'm digressing, but wanted to layout that it sure is appreciated having a range next door for zeroing in a new load. Here's what I found.
First, I quickly eliminated the lighter loads with .200 jump. I'm shooting paper at 100 yds, so it hurt my feelings when my early groups were sometimes 1 to 1.5 moa. Finally, at 76.8 grains of H1000, the groups started to close a little. .75 moa, but not great. My last loads for day 1 was at 77 grains and the moa was better at .500. At that point, I was out of my first test loads, but at least I'm closer to having a load and now know what didn't work. Back to the bench.
Second time out, I'm now stocked with 8 each of 76.8 to 78.5 grains of H1000 and COAL from 3.545 to 3.632. Immediately, the groups were .75 moa at 76.8 and 3.545 COAL (.090 off lands). Next, I shot some 77.8 grains at the same COAL, 3.545. The groups tightend up and two groups were at .375 to .400. This was exciting, since I knew I was closing in on my load. Next group was shot using the same 77.8 grains, but the COAL was now at 3.625, .010 off lands. I skipped some loads at 3.595 and went straight to the .010 off lands due to some excellent posts by others. It worked. The group was now .300 for only 3 shots, but a followup group using the same 77.8/3.626 was .320.
Finally, I moved on to the 78.2, 78.5, 78.8 grain loads at same COAL of 3.625 and shots immediately went back to .75 moa. I'll be testing 78 tomorrow at different COAL, but suspect the 77.8 is where I'll end.
That's where I am now, and based on chronograph information from others with similar loads, I suspect velocities in the 2850-2900 fps range, maybe a little more, but I forgot my new Chrony Alpha when I went out for the 2nd trip. Tomorrrow, I'll have the opportunity to test velocity as well as the .003 off lands with 77.8 and 78 grains H-1000. Hope this helps others.
The gun is an Armalite AR30A1 Target version of the .300 Win Mag. It has a 24" barrel, 1:10 twist rate and a factory break. I've added an Atlas bipod as well as a monopod on the stock. It comes standard with a long 20 moa rail and I've mounted an SIII 10-50x62 mm Sightron Mildot reticle scope. What I could not find posted was the chamber length and at what point the COAL would touch the lands. I've spent several days, learning and reloading, using H-1000 and the Hornady 208 A-max bullet. I've had excellent results with the A-max in my 6.5 Grendels, so I stuck with it.
What I didn't know was best seating depth, COAL, powder weight, etc specifically relating to the AR30A1. I loaded 5 pieces of brass at each powder weight in increments of .5 grains, beginning at 74 and stopping at 78.5. I also loaded 8 each in the 77 to 78.5 grain range with various COAL varying from 3.545, .090 off touching lands, to 3.632, .002 off lands.
My range is next door to my house. A close friend owns 600 acress and I've set up AR500 silhouette steel at every 100 yds from 100 to 1300 yards. Same target is used for 400 to 1300 yards. I'm digressing, but wanted to layout that it sure is appreciated having a range next door for zeroing in a new load. Here's what I found.
First, I quickly eliminated the lighter loads with .200 jump. I'm shooting paper at 100 yds, so it hurt my feelings when my early groups were sometimes 1 to 1.5 moa. Finally, at 76.8 grains of H1000, the groups started to close a little. .75 moa, but not great. My last loads for day 1 was at 77 grains and the moa was better at .500. At that point, I was out of my first test loads, but at least I'm closer to having a load and now know what didn't work. Back to the bench.
Second time out, I'm now stocked with 8 each of 76.8 to 78.5 grains of H1000 and COAL from 3.545 to 3.632. Immediately, the groups were .75 moa at 76.8 and 3.545 COAL (.090 off lands). Next, I shot some 77.8 grains at the same COAL, 3.545. The groups tightend up and two groups were at .375 to .400. This was exciting, since I knew I was closing in on my load. Next group was shot using the same 77.8 grains, but the COAL was now at 3.625, .010 off lands. I skipped some loads at 3.595 and went straight to the .010 off lands due to some excellent posts by others. It worked. The group was now .300 for only 3 shots, but a followup group using the same 77.8/3.626 was .320.
Finally, I moved on to the 78.2, 78.5, 78.8 grain loads at same COAL of 3.625 and shots immediately went back to .75 moa. I'll be testing 78 tomorrow at different COAL, but suspect the 77.8 is where I'll end.
That's where I am now, and based on chronograph information from others with similar loads, I suspect velocities in the 2850-2900 fps range, maybe a little more, but I forgot my new Chrony Alpha when I went out for the 2nd trip. Tomorrrow, I'll have the opportunity to test velocity as well as the .003 off lands with 77.8 and 78 grains H-1000. Hope this helps others.